A conventional method of mounting a mounting component on an FRP member includes a method of embedding a metal insert in the FRP member, and fastening the mounting component by use of a threaded hole of the insert.
For example, as shown in FIG. 8, Patent Document 1 discloses a technique of molding FRP after foam-forming a core 101 from a foam where a concave hole 102 is provided and placing a metal block 103 as an insert in the concave hole 102 (see FIG. 8(a)), forming a threaded hole 104 by tapping the internal metal block 103 through a coating made of FRP in an obtained FRP member 105 (see FIG. 8(b)), and mounting a mounting component 108 by screwing a bolt 107 into the threaded hole 104 (see FIG. 8(c)).
Meanwhile, when oil attaches to FRP, the FRP may be reduced in strength. Also, at the time of bonding the FRP members together by an adhesive, for example, adhesion therebetween may be inhibited by the oil attaching thereto, to thereby deteriorate adhesiveness. Thus, in the case of the aforementioned conventional method of forming the threaded hole 104 in the metal block 103 after molding the FRP member 105, the threaded hole 104 is formed not by wet machining that uses cutting oil, but by dry machining that does not use cutting oil.    Patent Document 1: JP Patent Publication (Kokai) No. 5-253946A (1993)